$20 \, cc$ of $CO_2$ are passed over red hot coke. The volume of $CO$ evolved is ............ $cc$.

If the density of methanol is $0.793 \ kg \ L^{-1}$,what volume is needed to prepare $2.5 \ L$ of a $0.25 \ M$ solution (in $mL$)?

Magnetite can be reduced with $CO$ to yield iron metal and carbon dioxide. Calculate the mass of magnetite (in $kg$) needed to obtain $4 \ kg$ of iron if the process is $80 \%$ efficient. [Atomic weight of $Fe$ and $O$ are $56 \ g$ and $16 \ g$, respectively]

When equal volumes of $0.1 \, M \, AgNO_3$ and $0.2 \, M \, NaCl$ are mixed,the concentration of $NO_3^-$ in the resulting mixture will be .......... $M$.

Dehydration of cyclohexanol $(C_6H_{11}OH)$ to cyclohexene $(C_6H_{10})$ gives a yield of $75\%$. If $100 \ g$ of cyclohexanol is dehydrated,what is the mass of the product obtained in grams?

How many grams of dibasic acid (mol. wt. $200$) should be present in $100 \ mL$ of its aqueous solution to give decinormal strength?